Fix double-encoding of display name in title and e-mails (#7534)

app/helpers/stream_entries_helper.rb

@@ -5,7 +5,11 @@ module StreamEntriesHelper
   EMBEDDED_ACTION = 'embed'
 
   def display_name(account, **options)
-    Formatter.instance.format_display_name(account, options)
+    if options[:custom_emojify]
+      Formatter.instance.format_display_name(account, options)
+    else
+      account.display_name.presence || account.username
+    end
   end
 
   def account_description(account)